Photocatalyst material, photocatalyst composition using the same and photocatalyst product
An object of the invention is to provide a photocatalyst material having a higher catalyst effect than conventional photocatalyst materials. The photocatalyst material of the invention contains, as its major component, a tungsten oxide powder excited by a light source which emits light having a wavelength of 430 to 500 nm, the photocatalyst material having a decomposition ability of 50% or more wherein the decomposition ability is given by the following equation based on the following test: [Test for decomposition ability]: 1 g of a tungsten oxide powder and 20 ppm of acetaldehyde (amount A) are poured into a 3-liter glass container, and acetaldehyde (amount B) is measured after light having a peak wavelength of 460 nm±10 nm is irradiated to the mixture for 2 hours to measure the decomposition ability (%): Decomposition ability (%)=[(acetaldehyde amount A−acetaldehyde amount B)/acetaldehyde amount A]×100.
1. A photocatalyst composition comprising 50% by mass or more of a photocatalyst material comprising, as its major component, a tungsten oxide powder having an average grain diameter of 0.5 μm or less and mainly containing monoclinic crystals, excited by a light source which emits light having a wavelength of 430 to 500 nm, with a peak wavelength of 460 nm+10 nm, wherein the photocatalyst material has a decomposition ability of 50% or more which is determined by the following equation based on the following test:
[Test for decomposition ability]
1 g of a tungsten oxide powder and 20 ppm of acetaldehyde (amount A) are poured into a 3-liter glass container, and acetaldehyde (amount B) is measured after light having a peak wavelength of 460 nm+10 nm is irradiated to the mixture for 2 hours to measure the decomposition ability (%):
Decomposition ability (%)=[(acetaldehyde amount A −acetaldehyde amount B )/acetaldehyde amount A]× 100.
2. The photocatalyst composition according to claim 1 , wherein the light source is a light-emitting diode using a blue light-emitting semiconductor element.
3. The photocatalyst composition according to claim 1 , wherein the light source is sunlight.
4. The photocatalyst composition according to claim 1 , wherein the light source is a fluorescent lamp.
5. The photocatalyst composition according to claim 1 , wherein dose of light having a wavelength of 430 to 500 nm is 1 mW/cm 2 or more.
6. The photocatalyst composition according to claim 1 , wherein the decomposition ability is 90% or more and 100% or less.
7. The photocatalyst composition according to claim 1 , comprising a monoclinic system as its major phase.
8. The photocatalyst composition according to claim 1 , comprising a titanium oxide powder in an amount less than 50% by mass.
9. A photocatalyst product comprising the photocatalyst composition according to claim 1 .
10. The photocatalyst product according to claim 9 , having a catalyst effect on at least one of an organic material, NO x and SO x .
11. The photocatalyst product according to claim 9 or 10 , wherein the photocatalyst composition is bound with a surface of a base substrate by a binder.
12. A photocatalyst composition comprising 50% by mass or more of a photocatalyst material comprising, as its major component, a tungsten oxide microparticle having an average grain diameter of 0.5 μm or less and mainly containing monoclinic crystals, excited by irradiation with blue light, wherein the photocatalyst material has a residual rate of acetaldehyde of 50% or less determined by the following equation based on the following test:
[Test for decomposition ability]
1 g of a tungsten oxide powder and 10 ppm of acetaldehyde are poured into a 3-liter glass container, and acetaldehyde is measured after the blue light having a peak wavelength of 460 nm+10 nm is irradiated to the mixture for 30 minutes to measure the residual rate of acetaldehyde (%):
Residual rate (%)=[(10 ppm acetaldehyde amount remained after 30 minutes)/10 ppm]×100.
13. The photocatalyst composition according to claim 12 , wherein a light source which emits blue light is a GaN system light-emitting diode having a light-emitting peak in the vicinity of 470 nm.
14. The photocatalyst composition according to claim 12 , comprising a monoclinic system as its major phase.
15. The photocatalyst composition according to claim 12 , comprising a titanium oxide powder in an amount less than 50% by mass.
16. A photocatalyst product comprising the photocatalyst composition according to claim 12 .
17. The photocatalyst product according to claim 16 , having a catalyst effect on at least one of an organic material, NO x and SO x .
18. The photocatalyst product according to claim 16 or 17 , wherein the photocatalyst composition is bound with a surface of a base substrate by a binder.